The present invention relates to a knitting needle used in a knitting machine. More particularly, the present invention relates to a compound needle comprising a needle body having a needle hook at its front end and a tongue constructed to be movable relative to the needle body and formed at the front end to cooperate with the needle hook so as to open and close the needle hook.
There is known a compound needle which comprises a needle body having a needle hook at its front end and a slider and is constructed so that the needle body and the slider can move relative to each other to open and close the needle hook. The applicant previously proposed this type of compound needle in Japanese Patent No. 2946323.
The previously proposed compound needle is so constructed that two blades of the slider are accommodated in an overlapped relation in a blade accommodation groove formed in the needle body. The blades are formed to have thickness smaller than width of the groove so as to form a gap between the blades and the groove walls so that the blades can be supported to freely advance and retract in the groove.
In the knitting machine using the compound needles as noted above, front ends of the two blades of the slider are brought into abutment with outward inclined surfaces of the needle hook of the needle body at the front end thereof, to be diverged right and left and then a knitting needle on the opposite needle bed is moved into the space formed between the two diverged blades advanced beyond the needle hook, whereby transference of a loop is performed. The space formed between the two blades varies depending on the widthwise dimension of the needle hook formed at the front end of the needle body. A rough gauge knitting machine uses the compound needles each having a large needle hook and, with increase in size of a stitch formed, the size and thickness of the needle hook increase. In the knitting machine disclosed by Japanese Patent No. 2946323 as previously cited, the two blades are placed on a center line of the needle passing through the front end of the needle hook in the overlapped relation in the blade accommodation groove. In the case of a compound needle of rough gauge and large thickness, this presents the disadvantage that when the blades are advanced beyond the needle hook, the slider is abutted with the needle hook and is diverged right and left with increased sliding resistance, so that a burden is imposed on the slider and the needle hook. Further, when the blades are moved to their advanced positions beyond the needle hook, the stretch of the blades increases to a large extent. This presents the problem for a knitting machine comprising a pair of front and back needle beds which are arranged in opposition to each other and on which knitting members, such as a sinker and a loop presser, are disposed adjacent to the compound needles, so as to be advanced and retracted with respect to a needle bed gap. Specifically, in this knitting machine, there is the possibility that when transference of a loop is performed, the blades may move closely to the knitting members to occupy the space for allowing the loop on the tongues to be transferred to a needle on the receiving side, thus causing a knitting problem. Increase in spacing between the needle hook and the blade groove can allow the stretch of the blades to reduce to that extent, but this leads to elongation of the needle body and the slider with respect to the lengthwise direction of the needle and further to increase in size of the carriage and the knitting machine itself.
It is the object of the present invention to disclose improvement of a compound needle of the type noted above, wherein the blades of the slider can be allowed to be advanced beyond the needle hook with a reduced sliding resistance of the blades of the slider and a reduced degree of stretch of the blades, as compared with the conventional compound needle.
The present invention provides a compound needle which comprises a needle body having a needle hook at a front end thereof and a slider having a tongue formed by two blades being combined in an overlapped relation and is so structured that the needle body and the slider are individually movable back and forth in the state in which the blades of the slider are supported in a blade groove formed in the needle body, wherein a partition wall having thickness smaller than that of the needle hook of the needle body is formed in the blade groove and the blades of the slider are accommodated in the blade groove to sandwich the partition wall therebetween. This construction of the compound needle of the invention can provide the result that when the slider is advanced beyond the needle hook, the two blades, which are abutted with the front end of the needle hook and diverged right and left by the side surfaces of the needle hook at the front end thereof, are made to advance along lines deviating from a center line of the needle passing through the front end of the needle hook by the partition wall, so that the blades are stretched to a reduced extent in a widthwise direction of the needle, as compared with the conventional compound needle wherein two blades are advanced along the center line of the needle passing through the front end of the needle hook.